All vehicles typically have a grille mounted on the front thereof. The grille has a plurality of openings that permit ambient air to flow into an engine compartment. The grille may be mounted on the front of the vehicle to protect an engine, a radiator, and the like in the engine compartment.
Further, the engine for driving the vehicle and various types of heat exchangers, such as a radiator, an intercooler, an evaporator, a condenser, and the like, are mounted in the engine compartment.
If ambient air is introduced through the openings of the grille, the ambient air may flow into the engine compartment to appropriately cool the engine, the heat exchangers, or the like and to decrease the temperature of the engine compartment, thereby preventing heat damage to the engine compartment.
When the vehicle travels at a low speed, ambient air may flow into the engine compartment through the openings of the grille at a relatively low flow rate. When the vehicle travels at a high speed, ambient air may flow into the engine compartment through the openings of the grille at a relatively high flow rate.
In the case where ambient air flows into the engine compartment through the openings of the grille at a relatively high flow rate, cooling efficiency (and the ability to prevent heat damage) may be enhanced. However, aerodynamic characteristics of the vehicle may be degraded due to the increase in the flow rate of ambient air. In contrast, in the case where ambient air flows into the engine compartment through the openings of the grille at a relatively low flow rate, cooling efficiency (and the ability to prevent heat damage) may be degraded, but aerodynamic characteristics of the vehicle may be improved.
As described above, the flow rate of ambient air may vary depending on a change in the speed of the vehicle. The cooling efficiency and the aerodynamic characteristics may conflict according to a change in the flow rate of ambient air.
In order to overcome these problems, an active air flap system that adjusts opening/closing of an air flap according to the speed of a vehicle, the temperature of ambient air, or the like may be applied. Such a system may appropriately adjust the flow rate of ambient air, the inflow direction of ambient air, or the like, thereby stably improving cooling efficiency and aerodynamic characteristics that conflict with each other.
However, the active air flap system has problems in that a motor for driving the air flap and a support structure for supporting a movement of the air flap have a complicated construction, which leads to high power consumption by the motor, an increase in manufacturing cost, and an increase in the weight of a vehicle.